Saturday, July 26, 2008

The Inuit: Lessons from the Arctic

The Inuit (also called Eskimo) are a group of hunter-gatherer cultures who inhabit the arctic regions of Alaska, Canada and Greenland. They are a true testament to the toughness, adaptability and ingenuity of the human species. Their unique lifestyle has a lot of information to offer us about the boundaries of the human ecological niche. Weston Price was fascinated by their excellent teeth, good nature and overall robust health. Here's an excerpt from Nutrition and Physical Degeneration:

"In his primitive state he has provided an example of physical excellence and dental perfection such as has seldom been excelled by any race in the past or present...we are also deeply concerned to know the formula of his nutrition in order that we may learn from it the secrets that will not only aid in the unfortunate modern or so-called civilized races, but will also, if possible, provide means for assisting in their preservation."

The Inuit are cold-hardy hunters whose traditional diet consists of a variety of sea mammals, fish, land mammals and birds. They invented some very sophisticated tools, including the kayak, whose basic design has remained essentially unchanged to this day. Most groups ate virtually no plant food. Their calories came primarily from fat, up to 75%, with almost no calories coming from carbohydrate. Children were breast-fed for about three years, and had solid food in their diet almost from birth. As with most hunter-gatherer groups, they were free from chronic disease while living a traditional lifestyle, even in old age. Here's a quote from Observations on the Western Eskimo and the Country they Inhabit; from Notes taken During two Years [1852-54] at Point Barrow, by Dr. John Simpson:

These people [the Inuit] are robust, muscular and active, inclining rather to spareness [leanness] than corpulence [overweight], presenting a markedly healthy appearance. The expression of the countenance is one of habitual good humor. The physical constitution of both sexes is strong. Extreme longevity is probably not unknown among them; but as they take no heed to number the years as they pass they can form no guess of their own ages.

One of the common counterpoints I hear to the idea that high-fat hunter-gatherer diets are healthy, is that exercise protects them from the ravages of fat. The Inuit can help us get to the bottom of this debate. Here's a quote from Cancer, Disease of Civilization (1960, Vilhjalmur Stefansson):

"They are large eaters, some of them, especially the women, eating all the time..." ...during the winter the Barrow women stirred around very little, did little heavy work, and yet "inclined more to be sparse than corpulent" [quotes are the anthropologist Dr. John Murdoch, reproduced by Stefansson].

Another argument I sometimes hear is that the Inuit are genetically adapted to their high-fat diet, and the same food would kill a European. This appears not to be the case. The anthropologist and arctic explorer Vilhjalmur Stefansson spent several years living with the Inuit in the early 20th century. He and his fellow Europeans and Americans thrived on the Inuit diet. American doctors were so incredulous that they defied him and a fellow explorer to live on a diet of fatty meat only for one year, under the supervision of the American Medical Association. To the doctors' dismay, they remained healthy, showing no signs of scurvy or any other deficiency (JAMA 1929;93:20–2).

Yet another amazing thing about the Inuit was their social structure. Here's Dr. John Murdoch again (quoted from Cancer, Disease of Civilization):

The women appear to stand on a footing of perfect equality with the men, both in the family and the community. The wife is the constant and trusted companion of the man in everything except the hunt, and her opinion is sought in every bargain or other important undertaking... The affection of parents for their children is extreme, and the children seem to be thoroughly worthy of it. They show hardly a trace of fretfulness or petulance so common among civilized children, and though indulged to an extreme extent are remarkably obedient. Corporal punishment appears to be absolutely unknown, and children are rarely chided or punished in any way.

Unfortunately, those days are long gone. Since adopting a modern processed-food diet, the health and social structure of the Inuit has deteriorated dramatically. This had already happened to most groups by Weston Price's time, and is virtually complete today. Here's Price:

In the various groups in the lower Kuskokwim seventy-two individuals who were living exclusively on native foods had in their 2,138 teeth only two teeth or 0.09 per cent that had ever been attacked by tooth decay. In this district eighty-one individuals were studied who had been living in part or in considerable part on modern foods, and of their 2, 254 teeth 394 or 13 per cent had been attacked by dental caries. This represents an increase in dental caries of 144 fold.... When these adult Eskimos exchange their foods for our modern foods..., they often have very extensive tooth decay and suffer severely.... Their plight often becomes tragic since there are no dentists in these districts.

Modern Inuit also suffer from very high rates of diabetes and overweight. This has been linked to changes in diet, particularly the use of white flour, sugar and processed oils.

Overall, the unique lifestyle and diet of the Inuit have a lot to teach us. First, that some humans are capable of being healthy eating mostly animal foods. Second, that some humans are able to thrive on a high-fat diet. Third, that humans are capable of living well in extremely harsh and diverse environments. Fourth, that the shift from natural foods to processed foods, rather than changes in macronutrient composition, is the true cause of the diseases of civilization.

19 comments:

I'm inclined to think you're right about the refinement/denaturing of foods being a significant factor, but I'm a bit surprised to see your fourth thing that "the Inuit have to teach us".

How does their no-carb lifestyle undermine the macro-nutrient position? I would have thought it was a bit the opposite. After all, it wasn't Caribou Lite(TM) and "I can't believe it's not Walrus(TM)" that the white man brought, and unfortunately he didn't bring fermented dairy and sprouted grains either. If he had, and they had continued to thrive, you might have a point.

The reason I believe macronutrients are not the culprit is that there are healthy cultures eating high-fat diets, low-fat diets and everything in between (past and present). The Kitavans are a good example of a high-carb, low-fat culture that does not suffer from the diseases of civilization. They eat root vegetables rather than grains. These cultures lose their good health when they introduce processed food into their diets, typically white flour, sugar and vegetable oils. That's irrespective of macronutrient levels.

I think low-carb is great for individuals who have already damaged their metabolism with processed foods (overweight and/or glucose problems), but it's not necessary for good health on a cultural level.

I always feel like something is missing when we analyze high fat diets. I have no dispute with the fact that a high fat diet makes you vigorous and strong. In fact, there is every indication that all causes of death are reduced -for a certain percentage of your life- when compared with a low fat diet. What i worry about is longevity. We can talk about insulin being low, low triglycerides, good HDL to LDL levels, but that doesn't paint the whole picture. I read a lot more entries out of the heart scan blog these days because i want to know concretely which people are getting heart disease. And let me say, there are plenty of people with an **outstanding** HDL to LDL level, decent trigs and large particle cholesterol that still have atherosclerosis. It's very possible that something happens to the fat we consume that damages our arteries in some way. And it's also possible that our body prefers to just make its own un-oxidized fat from carbs. Arguments for high consumption of saturated fats doesn't always hold up because you would have to assume that your body would primarily be burning them and not laying them down then burning them for energy (our body tries to maintain strict levels of fats in our tissues) and i don't want to causes a fatty acid inbalance. Next, what about the fact that a high fat diet sets up the body for higher circulating levels of IGF-1 and growth factors <--- while this is fanastic for building a strong body- there is evidence to suggest that this might be pro-aging. And i don't have to mention the pros of consuming a lower protein diet (many research papers are abound that show protein restriction leads to increases in longevity <----- and might be primarily due to methionine restriction. So, what in want to see now is more research done on the level of fat that is truly optimal for longevity (and what breakdown of fats that entails--- WE NEED MORE RESEARCH!). And i also wanted to mention that even though i love sites like WAP (exposing nutritional misbeliefs and promoting an unprocessed diet). Having perfect teeth might mean nothing in terms of longevity. There may be some factor going on that prevents you from having perfect teeth in childhood and also leads you to greater longevity in the long run(notice how shorter people liver longer -lower growth factors!!-. Im in the club of people who believe that your DNA don't really care about you. When you provide a diet that really makes your better at reproducing and being robust (you seem to burn out quicker--- to make room for your offspring <---- makes sense) if you eat a diet that covers all the basics but is sparse in calories<--- your DNA keeps you around for another day. That might just mean a lower fat diet--- someone needs to solve this

The summary that the link to changes in diet at PubMed refers to says that, "Although snacking is a concern, dietary fat was the most significant factor in obesity and NIDDM." I wonder if they are referring to an increase in the consumption of vegetable cooking oils, dairy or non-traditional animal fat sources. It would be interesting to know how much refined sugar and flour they consume now as this is the likely culprit I would have thought.

I published a post on the lifespan of traditionally-living Inuit a few weeks ago. About 25% of them made it past 60, and a significant number made it past 90. I'd say that's pretty good for a hunter-gatherer culture living in the arctic without any modern medicine (as a side note, the data were collected after they had been exposed to European diseases, thus may have actually underestimated their natural lifespan). To me, these empirical data trump hypothetical concerns about IGF-1 etc.

I am not suggesting that an Inuit-type diet is the only way to be healthy, only that it is one way. As for the tooth decay, I think it's just a marker of overall health (on a cultural level, and often on an individual level as well). Tooth decay is associated with heart disease and other health problems. I see it as a rough external marker of health.

On a hypothetical level, I'm open to the idea that there could be a difference between living vigorously and living long. Besides a few rare mutants, I'm not aware of any empirical evidence that it's the case. Maybe you could say that about caloric restriction though. You can live longer if you're willing to be skinny, cold and hungry for the rest of your life.

While I was searching for lectins I was brought to this page. I was really positively surprised, when I saw, that Stephan is having almost identical view on how nutrition is influencing on our health as I. It all became clearer, when I realized, that we both very highly value Weston Price's work. I bought his book "Nutrition and physical degeneration" 6-7 years ago (it is also on torrents now) and I have been supporter of his idea ever since.

As for saturated fats and dietary cholesterol, I believe, that both of them are harmless and even necessary for good health. Atherosclerosis, with which are they associated, is not caused by them, but probably by lectins (most aggressive and widely consumed are those in wheat), which cause harm on arterial blood vessels. Lipids and cholesterol are then stick to it as consequence. I even speculate, that if at time of damage there is not enough cholesterol in blood, body makes some deliberatly, so that walls of artery where damage have been done could been patched up with it. As I see it, that is lesser evil from two.

Glad to have someone else around who is familiar with Weston Price! When I first read Nutrition and Physical Degeneration, I didn't know what to make of it since it was so different from the info I had at the time. Since then, pretty much all the research I've done has bolstered Price's findings. His observations were universally corroborated by field physicians around the world. It's really been uncanny, especially the "activator X"/vitamin K2 thing.

Aaron I don’t find the longevity and sirtuin studies convincing. This has only been demonstrated in rodents and I don’t consider rat chow optimum for rats. Feed less junk food to rats and they live longer.

I agree, there are a number of things you can add to mouse/rat chow that make them healthier that seem to have no effect on humans. Antioxidants are a good example. It may simply be because the regular chow is such awful stuff that just about anything improves it.

Furthermore, genetically wild mice live longer and are more resistant to disease than their inbred counterparts. The average mouse strain is so inbred that any two mice from the same strain are as closely related as siblings would be in the wild.

Well what can you do, that's the limitation of laboratory research under controlled conditions. You just have to be ready to interpret your results cautiously!

This is Donny, not Jim. I don't trust the software not to lose my comment if I switch over. Hello.

All the low protein and low methionine studies show is that on a very specific diet, lowering the methionine or the protein extends rodent life span.

On the methionine thing, when you feed rats excess methionine, there are higher levels of damaged fats in their livers. Glycine administration reverses this. Adding glycine to the diet in this way limits delta-6 desaturase activity. Less unsaturation of fats, less damaged fat in the liver. The glycine also lowers homocysteine. Animals with tissues with a higher degree of saturation live longer. Maybe methionine restriction just addresses a methionine/glycine imbalance in the rat chow? They'd better check on the lysine/methionine, glutamic acid/methionine, ad nauseum/methionine balance while they're at it. The methionine study authors claim that the benefits of calorie restriction are because of methionine restriction, but they've never replicated the life extension results of calorie restriction.

Thanks Donny, those sound like interesting data. In yeast, restricting several sulfur-containing amino acids (including met) extends lifespan. I can't remember the proposed mechanism off the top of my head.

Really enjoyed this post, Stephan. One question: the 1929 JAMA article you cite reporting on the effects of the all-meat diet had this to say about one of the explorers:

"Of interest was the fact that the dextrose tolerance test, consisting of the ingestion of 100 Gm. of dextrose, developed in Andersen a typical diabetic curve resulting in the spilling of sugar for the two following days." (p22, mid-right)

I'm not really sure what this means (particularly the "spilling of sugar"), but it sounds as if Andersen was showing signs of diabetes-- which would contradict your statement that they showed "no signs of scurvy or any other deficiency". Am I misinterpreting this?

Sean its pretty normal for someone to test like that after months of being keto. If the test had been repeated daily for a few days you would see it quickly returned to normal. Ketosis induces a temporary insulin resistance. Its one reason those who do very low carb must return to 150 gram of carb a day or so for a good week before doing glucose tolerance tests or the result is way off.

However, sea mammals contain a super high amount of Omega 3 fats. It is not exactly the same as eating any animal meat. Sea mammals also have a fairly high amount of carbohydrate so it is not exactly accurate to say they ate zero carbs.

About Me

I'm a writer and science consultant with a background in neuroscience and obesity research. I have a BS in biochemistry and a PhD in neurobiology. I'm the author of "The Hungry Brain: Outsmarting the Instincts That Make Us Overeat".

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